<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:10pt"><DIV style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman, new york, times, serif">Comments below...<BR><BR>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif">----- Original Message ----<BR>From: Bob Briscoe <rbriscoe@jungle.bt.co.uk><BR>To: Dirceu Cavendish <dirceu_cavendish@yahoo.com><BR>Cc: Matt Mathis <mathis@psc.edu>; iccrg@cs.ucl.ac.uk<BR>Sent: Saturday, April 5, 2008 3:42:24 AM<BR>Subject: Re: [Iccrg] Heresy following "TCP: Train-wreck"<BR><BR>Dirceau,<BR><BR>At 21:29 04/04/2008, Dirceu Cavendish wrote:<BR>>Regarding place in the network, I mean everywhere - I guess all, as <BR>>per your question.<BR><BR>So then, a follow-on question is: if there are flows passing through <BR>router R1 from a user, how does R1 take account of flows from the <BR>same user not going through R1 at all?</DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif"><BR>IOW, I'm questioning whether the fairness question should be focused <BR>on sharing out each link (whether between flows or users) as it has <BR>been for the last n decades, or whether that was a distraction <BR>because we should have been looking at how much traffic is crossing <BR>trust boundaries between the principals (individuals, organisations, <BR>network operators), and how much of that traffic is causing <BR>congestion on /any/ other link. For instance, you have to be able to <BR>bring swarmcasting (e.g. BitTorrent) into your fairness framework.<BR></DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif"><dc> The routing of TCP sessions is typically not under control of the application. Otherwise, I agree that it is difficult to enforce even the simple link level share of resources.</DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif">About BitTorrent type of applications, it would be nice to have some sort of fairness concept between these types of application, and across to other applications. But then, assuming there are N types of applications in the Internet (which I dont have to say N can be large), one would need to provide fairness definitions for N(N-1) cases.</DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif">So I guess the question is: where do we stop with the fairness issue. We can draw a parallel with security - how much paranoid are we about it :-)</DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif">Cheers,</DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif">Dirceu</DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif"><BR>I think that's where Matt is going as well - moving the focus of <BR>fairness to the edges (the trust boundaries).<BR><BR><BR>Bob<BR><BR><BR>____________________________________________________________________________<BR>Bob Briscoe, <<A href="mailto:bob.briscoe@bt.com" ymailto="mailto:bob.briscoe@bt.com">bob.briscoe@bt.com</A>> Networks Research Centre, BT Research<BR>B54/77 Adastral Park,Martlesham Heath,Ipswich,IP5 3RE,UK. +44 1473 645196 <BR><BR><BR></DIV><BR></DIV></div><br>
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